The disclosure relates to near-net or net shape fused silica glass articles. In particular, the disclosure relates to radomes for missiles and other projectiles and other fused silica glass articles, such as crucibles for silicon wafer manufacturing having high strength and low thermal expansion at high temperatures.
Hypersonic missiles travel through the atmosphere at speeds in the mach 5-7 range and higher. The nose cones (also referred to as “radomes”) of such missiles house radar and other targeting sensors such as, for example, infrared (IR) sensors. At such speeds, missile components can be exposed to temperatures of about 1400° C. or greater for several minutes. Radomes must retain electrical and thermal performance under such conditions.
Radomes have been made from ceramic glasses, such as PYROCERAM® (Corning glass code 9606), having low coefficients of thermal expansion. However, such materials no longer meet the mechanical requirements associated with higher performance (e.g., increased speed, weather resistance).
Fused silica soot that has either been pressed, spin-cast, or slip-cast has also been evaluated as a radome material. While such materials have higher tolerance for heat and lower transmission losses than PYROCERAM, their permeability to moisture limits the ability of radomes made from such materials to protect electronics enclosed therein.